Dr. Brach is a physical therapist and a board certified geriatric clinical specialist who aims to become a nationally-recognized leader in the field of mobility and aging research. Physical therapists are experts in the examination and treatment of musculoskeletal and neuromuscular problems that affect mobility. Therefore, physical therapists should play an important role in the multidisciplinary approach to treating mobility problems and should be key players in research aimed at improving mobility. As a physical therapist Dr. Brach has developed strong skills in the assessment and treatment of mobility problems, and her training in epidemiology has given her a strong foundation in research methods and basic statistical techniques. She now seeks additional focused training in longitudinal data analysis, advanced gait analysis (including time series analysis), and clinical trial methodology. As her primary mentor on the proposed Paul B. Beeson Career Development Award in Aging, Dr. Stephanie Studenski, herself a national leader in mobility and aging research, will supervise Dr. Brach's research training and career development towards becoming an independent investigator and leader in the field of aging. Her research program and career development will be overseen by a multi-disciplinary team including an Epidemiologist/Geriatrician, a Statistician, a Bioengineer, and a Physical Therapist. The rich resources of the University of Pittsburgh Claude D. Pepper OAIC will also be utilized for her support and development. In line with her goal of becoming a nationally recognized leader in the field of aging and mobility, Dr. Brach designed a series of three research projects that will allow her to examine in detail gait variability and adaptability, a component of mobility. In project 1, Dr. Brach will use an established dataset from the Cardiovascular Health Study to examine the contributors and consequences of gait variability in a biracial sample of over 500 older adults. Since many older adults with mobility problems are not identified when tested under low demand situations, in project 2 Dr. Brach will develop a measure of gait adaptability to test older persons walking under high demand conditions. The final project (project 3) will be a small RCT to examine exercise interventions to improve gait variability and adaptability in older persons.